Habitat

Favorable habitat is a mixture of savanna woodlands and grassland. Woodlands consist of fire-resistant, broadleaf deciduous trees scattered over an under story of sparse grasses that are grazed during the rainy season. Dry season feeding grounds are grassland areas that were once flooded, then burned, subsequently producing new growth. If possible, Hippotragus niger avoids extensive open lands (Estes 1993).

Physical Description

This stunning antelope rivals even the most handsome kudus and is a popular zoo animal. Hippotragus niger has a powerful, robust build and a thick neck outlined by a vertical mane atop sturdy legs. Males and females are strikingly similar until 3 years old, when males become darker and develop majestic horns. Males weigh around 238 kilograms at a height of 116-142 centimeters. Females weigh 220 kilograms and are slightly shorter than males. The horns are massive and more curved in males reaching lengths of 81-165 centimeters, while females' horns are only 61-102 centimeters in length. Coloration in bulls is black, females and young are chestnut except in southern populations, where females turn brown-black. Most sable antelope have white “eyebrows”, a rostrum sectioned into cheek stripes, white belly and rump patch. Young under 2 months typically are light brown and have slight markings (Estes 1993).

Reproduction

Dominant males defend harems of females and their immediate foraging territory extending 300 to 500 meters out from the herd. These dominant males mate with females in their harem and vigorously defend them against intruding males (see behavior section). Males may drop to their knees and engage in horn wrestling in fights. Fatalities from these fights are rare.

Hippotragus niger females usually undergo only one estrous cycle per breeding season that last from May to July, with a peak mating in June. Gestation lasts 8 to 9 months, allowing for birth at the end of rains. Normally one calf is born during the end of the rainy season when long grass is available for cover. The mother stays concealed for the first week of the calf’s three-week hiding phase. After the first week, the mother joins a maternal group that the calf will eventually join. Yet, the calf will seek out the mother only for nursing. In fact, the mother-offspring bond is so feeble, even small calves will spend days apart in a divided herd. Weaning takes place six months after birth, usually towards the end of the dry season when “sourveld” vegetation is lowest in protein and other nutrients (Wilson and Hirst 1977). Females start to breed at 2.5 years old and congregate in social groups that are a rank hierarchy based on seniority. Males are subordinate to females until they are bigger. At 3 to 4 years of age males are evicted from female social groups and live in bachelor herds until they reach sexual maturity at 5 years (Estes 1993).

Behavior

Sable antelope are both nocturnal and diurnal, although they prefer to feed just until dark, because of a high risk of predation at night. Most sable antelope will travel roughly a mile a day and even less during the dry season (
http://library.thinkquest.org/16645/wildlife/sable_antelope.shtml). The mating season for sable antelopes occurs during the dry-season when sub-populations congregate on remaining green pastures. Herds consist of many females (15-25 members) and young, along with one dominant male. Males set up their territories in the best grazing areas to attract females and only a few dominant males will be able to hold those territories. The dominant male will allow subordinate males to graze in his territory as long as they are submissive and show no interest in females. Males will fight if the territory of a male is challenged, but fights to the death are rare. There are a few behavioral differences between males and females. Males make scrape markings by pawing dung sites. Males also engage in herding, chasing and foreleg lifting used by courting males to prod reluctant females (Estes 1993).

Communication and Perception

Food Habits

Typically, sable antelope are specialized grazers feeding on foliage and herbs, especially those growing on termite mounds. During the dry season they are less reluctant to browse (Estes 1993). One of the reasons for declining antelope numbers could be their very specific feeding pattern. Typically they will feed on grasses (up to ninety percent of their diet) at heights of 40-140 millimeters from the ground taking only the leaf. In a savannah setting, sable antelope are the last to feed on the new grasses available during the late dry season when food availability is vital (Spinage 1986). In the paddock setting, where grasses are tall (above 140mm), feed is high in protein and low in fiber, and sable antelope quickly lose weight. In a particular enclosure study, sable antelope fed primarily on Brachiaria nigropedata, which only had a frequency occurrence of 3.9% across the study area (Wilson and Hirst 1977). The correlation of neck length, angle of the jaws and selective feeding habits serves to separate Hippotragus niger from other grazers and suggests why they are habitat limited (Spingage 1986). Water is visited at least every other day and no sable antelope will travel more then 2 miles from a watering hole or river. Salt licks are visited periodically and they will chew on bones to get trace essential elements not present in mineral-deficient soil (Estes 1993).

Predation

Lions seldom attack adults, because of their size and the formidable fighting abilities of these antelope. Humans are the only real threat to adult sable antelope and their populations (Spinage 1986). Young Hippotragus niger are susceptible to predation by lions, leopards, hyenas, African hunting dogs and crocodiles.

Ecosystem Roles

Sable antelope help to cycle grass/plant nutrients into other areas and the young are prey for large predators.

Economic Importance for Humans: Positive

Sable antelope are found in parks all across eastern and southern Africa offering an attraction to the ecotourism industry. Sable antelope are prized trophy animals to many big-game hunters and some are willing to spend thousands of dollars to hunt them. However, declining sable antelope numbers calls into question the advisability of hunting them.

Economic Importance for Humans: Negative

Sable antelope have no negative affects on humans.

Conservation Status

IUCN lists Hippotragus niger as lower risk and conservation dependent, but declining numbers could lead to a threatened listing in the near future. The subspecies Hippotragus niger variani is listed as endangered due to habitat loss and trophy hunting. Studies in the past show that a complex blend of factors such as disease, malnutrition, and habitat quality compounded by interspecific competition and attempts to manipulate populations have limited sable antelope numbers. Historic data has demonstrated their tendency to be dense in some regions and practically nonexistent in others, even in well managed national parks (Wilson and Hirst 1977).

Contributors

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

nomadic

generally wanders from place to place, usually within a well-defined range.

polygynous

having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.